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Highlights from the 8th International Conference on Predictive Modelling in Food (ICPMF8)
No full textTecnologias de biopreservação e novas abordagens de modelação para controlar o desenvolvimento de Staphylococcus aureus em queijos frescos de leite cru de cabra
No full textTese de doutoramento em Food Science and Technology and NutritionA presença de Staphylococcus aureus em queijos frescos de leite cru de cabra tem sido
documentada várias vezes. Nestes queijos, não existe uma fase de maturação prolongada que
reduza a carga do patogénico e a pasteurização não é utilizada para garantir as características
sensoriais únicas associadas a queijos de leite cru. Assim, esta tese teve como objetivo fornecer
soluções para melhorar a qualidade microbiológica deste produto em relação à contaminação por
S. aureus. Para tal, testou-se a incorporação de extratos de plantas em queijo, a utilização de uma
cultura de arranque no leite, e um tratamento térmico moderado do leite (termização), usando
modelos preditivos para avaliar o efeito destas estratégias na sobrevivência de S. aureus.
Os extratos de plantas avaliados (alfazema, erva-cidreira, estragão, hortelã, manjericão e
sálvia) apresentaram várias bioatividades relevantes, entre elas a antimicrobiana, atribuídas aos
seus perfis fenólicos. Foi evidente a influência do tipo de solvente e extração no perfil fitoquímico
e bioatividades obtidas, o que levou à seleção de três extratos hidroetanólicos (erva-cidreira, hortelã
e sálvia) para incorporação em queijo como bioconservantes. Entre as bactérias ácido-láticas
isoladas de queijos artesanais, várias demonstraram capacidade antimicrobiana e acidificante.
Pelas suas características promissoras, as estirpes L. mesenteroides, L. paracasei, L. cremoris e
L. lactis foram selecionadas para a produção de uma cultura de arranque.
As várias temperaturas de termização testadas (55 a 64 °C) foram eficazes na inativação
de S. aureus em leite, conforme revelaram os modelos, ainda que produzindo efeitos distintos na
capacidade de sobrevivência do patogénico. A abordagem de modelação global mostrou estimativa
de parâmetros aprimorada, comparando com a modelação em dois passos.
Por último, através de modelos dinâmicos (baseados na equação de Bigelow), o efeito
inibitório dos extratos vegetais e da cultura de arranque adicionados ao queijo/leite foi validado ,
demonstrando que a adição de qualquer um dos bioconservantes reduz o tempo necessário para
reduzir em um log a concentração de S. aureus.
No geral, os modelos preditivos construídos permitiram confirmar a eficácia da termização
e dos métodos de biopreservação testados no controlo de S. aureus, oferecendo assim soluções
para melhorar a qualidade microbiológica de queijos artesanais de leite cru de cabra.The presence of Staphylococcus aureus in goats’ raw milk soft cheeses has been
documented several times. In these cheeses, there is no prolonged ripening stage that reduces the
pathogen load, and pasteurisation is not used to ensure the unique sensory characteristics
associated with raw milk cheeses. Thus, this thesis aimed to provide solutions to improve the
microbiological quality of this product in terms of S. aureus contamination. For that, the
incorporation of plant extracts in cheese, the use of a customised starter culture in milk, and a
mild thermal treatment of milk (thermisation) were tested, and predictive models were used to
evaluate the effect of these strategies on the survival of S. aureus.
The evaluated plant extracts (French lavender, lemon balm, tarragon, spearmint, basil and
sage) showed several relevant bioactivities, including antimicrobial activity, which were attributed
to their phenolic profiles. The influence of the type of solvent and extraction on the phytochemical
profile and bioactivities obtained was evident, which led to the selection of three hydroethanolic
extracts (lemon balm, spearmint and sage) to be incorporated into cheese as biopreservatives.
Among the lactic acid bacteria isolated from artisanal cheeses, several showed antimicrobial and
acidifying capacity. Due to their promising characteristics, L. mesenteroides, L. paracasei, L.
cremoris and L. lactis strains were selected to produce a starter culture.
The various thermisation temperatures tested (55 to 64 °C) were effective in inactivating
S. aureus in milk, as shown by the adjusted models (Weibull), although producing different effects
on the pathogen's ability to survive. The global modelling approach showed improved parameter
estimation compared to the two-step modelling.
Finally, through dynamic models (based on the Bigelow equation), the inhibitory effect of
plant extracts and starter culture added to cheese/milk was validated, demonstrating that the
addition of any of the biopreservatives reduces the time required to reduce the concentration of S.
aureus by one log.
Overall, the predictive models built allowed confirming the effectiveness of thermisation
and the biopreservation methods tested in controlling S. aureus, thus offering solutions to improve
the microbiological quality of artisanal goats’ raw milk cheeses.Este trabalho foi financiado pelo Fundo Social Europeu e por fundos nacionais da Fundação para a Ciência e Tecnologia (Ministério da Ciência, Tecnologia e Ensino Superior) através da bolsa de doutoramento SFRH/BD/137801/2018. É também reconhecido o apoio do programa EU PRIMA e da Fundação para a Ciência e Tecnologia pelo financiamento do projeto ArtiSaneFood (PRIMA/0001/2018)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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